1. Field of the Invention
This invention relates generally to a technique for isolating segments of a serial data bus. More particularly, this invention relates to an automatic system for initializing, or configuring, multiple terminal units, attached to a serial data bus, without requiring physical access to the plurality of remote terminal units, each of which may be located at or near a passenger seat of a passenger vehicle, such as an aircraft, train or bus, for example, or in a theater or stadium or the like.
2. Background of the Invention
In-flight entertainment systems commonly installed in modern passenger aircraft provide both increased passenger satisfaction as well as a revenue stream to airlines, by making a number of entertainment options available to the passengers. Well-known systems such as those shown, for example, in U.S. Pat. Nos. 4,866,515 (Tagawa) and 4,835,604 (Kondo), disclose a number of methods of providing audio and video in-flight entertainment to airline passengers.
It should be appreciated that the need to have the ability to easily and quickly configure each of the individual units or components, of an in-flight entertainment system, once installed in an aircraft, is invaluable. For example, in many instances the misconfiguration of a component in an in-flight entertainment system will result in the need for corrective action which requires disassembly of interior aircraft cabin panels. These corrective actions may result in aircraft departure delays, or, the misconfigured component may cause the entire system to be inoperative. Even if the initial installation of the system is correctly performed, the maintenance and upkeep of the system normally requires periodic physical access to the individual components.
Although various manual methods of addressing and configuration of individual video distribution units have been known for quite awhile, the problem of manually performing these functions has become more significant in the recent past in view of the increase in complexity of onboard electronic systems and the decrease in space and weight allotted to such systems. These factors greatly increase the cost, in both time and equipment, in both installation and maintenance of the system.
Known methods of initializing individual units attached to a serial data bus include physically accessing each unit and configuring each unit manually with, for example, DIP switch settings, internal configuration jumpers or plugs, jumpers in the cable harness, etc. However, as discussed, the standard "manual" approaches are both uncertain and inefficient. The present invention addresses each of these needs.